Clinical Neuroradiology最新文献

Over the past decade, major advances have transformed the understanding and management of cerebrospinal fluid (CSF) leaks leading to spontaneous intracranial hypotension (SIH). Among the most impactful developments has been the identification and characterization of CSF-venous fistulae (CVF), a distinct and still underrecognized cause of SIH. This discovery has prompted a paradigm shift in both diagnostic and therapeutic strategies. Novel imaging techniques-including lateral decubitus CT myelography and digital subtraction myelography-have markedly improved detection rates, while targeted interventions such as transvenous embolization have emerged as safe and effective treatment options. In this review, we first outline the general pathophysiology and imaging principles related to SIH and CSF leaks, followed by a focused and comprehensive analysis of the current evidence managing CVFs. We discuss their diagnostic challenges, therapeutic approaches, and evolving clinical implications, aiming to provide a thorough update for diagnostic and interventional neuroradiologists involved in the care of patients with SIH.

Selection of appropriate imaging sequences protocols for cranial magnetic resonance imaging (MRI) is crucial to address the medical question and adequately support patient care. Inappropriate protocol selection can compromise diagnostic accuracy, extend scan duration, and increase the risk of misdiagnosis. Typically, radiologists determine scanning protocols based on their expertise, a process that can be time-consuming and subject to variability. Language models offer the potential to streamline this process. This study investigates the capability of bidirectional encoder representations from transformers (BERT)-based models to suggest appropriate MRI protocols based on referral information.A total of 410 anonymized electronic referrals for cranial MRI from a local order-entry system were categorized into nine protocol classes by an experienced neuroradiologist. A locally hosted instance of four different, pre-trained BERT-based classifiers (BERT, ModernBERT, GottBERT, and medBERT.de) were trained to classify protocols based on referral entries, including preliminary diagnoses, prior treatment history, and clinical questions. Each model was additionally fine-tuned for local language on a large dataset of electronic referrals.The model based on medBERT.de with local language fine-tuning was the best-performing model and correctly predicted 81% of all protocols, achieving a macro-F1 score of 0.71, macro-precision and macro-recall values of 0.73 and 0.71, respectively. Moreover, we were able to show that local language fine-tuning led to performance improvements across all models.These results demonstrate the potential of language models to predict MRI protocols, even with limited training data. This approach could accelerate and standardize radiological protocol selection, offering significant benefits for clinical workflows.

Background and purpose: Incomplete reperfusion in endovascular thrombectomy (EVT) impacts patients' outcomes. Different incomplete reperfusion patterns may benefit from targeted therapeutic strategies, e.g. EVT-accessible incomplete reperfusion patterns could improve by performing additional EVT attempts, while EVT-non-accessible incomplete patterns might benefit from pharmacological therapies. The health-economic implications of these therapies are uncertain. This study aims to assess the potential economic benefits of improving incomplete reperfusion patterns after EVT.

Materials and methods: Retrospective Data analysis from the ESCAPE-NA1 trial, which included patients with large vessel occlusion strokes undergoing EVT. Reperfusion patterns were classified as near-/complete (eTICI 2c3), EVT-accessible incomplete (eTICI 2b), or EVT-non-accessible incomplete (eTICI 2b) and we compared multiple attempts to achieve eTICI 2c3 vs. first-pass eTICI 2c3. A Markov-Model was built to compare lifetime costs and quality adjusted life-years (QALY) for each reperfusion pattern over a lifetime horizon, considering both healthcare and societal perspectives.

Results: A total of 1105 of patients were enrolled in the ESCAPE-NA1 trial of which 949 with eTICI 2b, 2c and 3 were further analyized (mean age 70.7 ± 13.6 [SD]; 463 female). Near-Complete reperfusion (eTICI 2c3) was achieved in 506/1105 patients (45.8%). Incomplete reperfusion patterns (eTICI 2b) were found in 450/1105 (40.7%) patients. Angiography imaging could be further investigated in 443/450 (98.4%) cases with 147/443(33.2%) EVT-accessible and 296/443(66.8%) EVT-non-accessible incomplete reperfusion patterns. Compared to EVT-accessible and EVT-non-accssible incomplete reperfusion, achieving complete (eTICI 2c3) reperfusion resulted in lower costs and an additional 1.14/0.45 QALYs, making it the dominant strategy from a health-economic perspective. In the complete reperfusion (eTICI 2c3) group, cumulative lifetime QALYs were similar with 5.25 for single-pass eTICI 2c3 and 5.19 for multi-pass eTICI 2c3.

Conclusions: Improving incomplete reperfusion patterns after EVT has considerable potential health economic benefits, both in the presence and absence of a target occlusion that is amenable to EVT.

Background: Non-contrast computed tomography (NCCT) is a first-line imaging technique for determining treatment options for acute ischemic stroke (AIS). However, its poor contrast and signal-to-noise ratio limit the diagnosis accuracy for radiologists, and automated AIS lesion segmentation using NCCT also remains a challenge. This study aims to develop a segmentation method for ischemic lesions in NCCT scans, combining symmetry-based principles with the nnUNet segmentation model.

Methods: Our novel approach integrates a Generative Module (GM) utilizing 2.5 D ResUNet and an Upstream Segmentation Module (UM) with additional inputs and constraints under the 3D nnUNet segmentation model, utilizing symmetry-based learning to enhance the identification and segmentation of ischemic regions. We utilized the publicly accessible AISD dataset for our experiments. This dataset contains 397 NCCT scans of acute ischemic stroke taken within 24 h of the onset of symptoms. Our method was trained and validated using 345 scans, while the remaining 52 scans were used for internal testing. Additionally, we included 60 positive cases (External Set 1) with segmentation labels obtained from our hospital for external validation of the segmentation task. External Set 2 was employed to evaluate the model's sensitivity and specificity in case-dimensional classification, further assessing its clinical performance. We introduced innovative features such as an intensity-based lesion probability (ILP) function and specific input channels for suspected lesion areas to augment the model's sensitivity and specificity.

Results: The methodology demonstrated commendable segmentation efficacy, attaining a Dice Similarity Coefficient (DSC) of 0.6720 and a Hausdorff Distance (HD95) of 35.28 on the internal test dataset. Similarly, on the external test dataset, the method yielded satisfactory segmentation outcomes, with a DSC of 0.4891 and an HD 95 of 46.06. These metrics reflect a substantial overlap with expert-drawn boundaries and demonstrate the model's potential for reliable clinical application. In terms of classification performance, the method achieved an Area Under the Curve (AUC) of 0.991 on the external test set, surpassing the performance of nnUNet, which recorded an AUC of 0.947.

Conclusion: This study introduces a novel segmentation technique for ischemic lesions in NCCT scans, leveraging symmetry-based principles integrated with nnUNet, which shows potential for improving clinical decision-making in stroke care.

Purpose: Prognosis and therapeutic approaches to meningiomas are determined by their proliferative activity and tumor grade. The early identification of aggressive phenotypes is hence essential to improving outcomes. Here, we investigated the potential of shape-based radiomics features and surface regularity (SR) as non-invasive biomarkers of atypical (grade 2) and anaplastic (grade 3) meningiomas.

Methods: In this retrospective single-center study, we assessed individuals with treatment-naive meningiomas in a comprehensive analysis of MR imaging with histopathological grading and quantification of mitotic activity. Radiomics (sphericity, elongation, flatness) and SR measures were calculated on segmented contrast-enhancing tumor components and tested for association with WHO grade (n = 62 grade 1, n = 71 grade 2, and n = 19 grade 3) and proliferation.

Results: All tumor grades were significantly different in characteristics of sphericity and SR with decreasing values at higher tumor grades as an expression of a more irregular shape. Additionally, radiomics features of tumor elongation and flatness discriminated grade 3 cases from grade 1 (p = 0.0008 and p = 0.0003) and grade 2 meningiomas (p = 0.0008 and p = 0.0013). Mitotic activity exhibited a significant negative correlation with the four imaging markers assessed (p < 0.003).

Conclusion: Shape-based radiomics features of sphericity and SR can serve as preoperative grading biomarkers of meningiomas in routine contrast-enhanced T1w MRI.

Purpose: Middle meningeal artery (MMA) embolization has emerged as a promising alternative or supplement to surgery for chronic subdural hematoma (cSDH). However, the effectiveness of different embolic agents remains unclear.

Methods: We systematically reviewed 41 studies published up to September 2025, including 8 meta-analyses, 1 scoping review, and 32 clinical cohorts or series. Embolic agents evaluated included liquid agents (Onyx, Squid, n‑BCA), particulates (polyvinyl alcohol [PVA], microspheres), and coils. The primary endpoint was treatment failure, defined as symptomatic or radiological recurrence of cSDH requiring repeat intervention (repeat MMA embolization or surgical rescue); secondary outcomes included complications, mortality, and functional outcomes.

Results: No embolic agent demonstrated consistent superiority in randomized trials, meta-analyses, or observational cohorts. Pooled recurrence rates were lowest with n‑BCA (0.8%), followed by Squid (3.6%), Onyx (4.4%), PVA particles (7.3%), and coils (9.0%). Although pooled recurrence appeared lowest with n‑BCA and highest with coils, most randomized and observational comparative studies did not detect statistically significant differences between embolic agents. Major complications were infrequent (≈1-3%) and similar across agents. Liquid embolics had significantly higher costs than PVA particles but did not lead to improved functional outcomes.

Conclusion: MMA embolization is a safe and effective treatment for cSDH. Outcomes are generally similar across different embolic agents, and selection should be based on anatomical factors, operator expertise, and resource availability rather than expectations of agent-specific effectiveness.

Introduction/background: The rising demand for endovascular stroke therapy highlights the need for standardized training environments. Studies have shown the positive impact of simulator-based training for neurointerventional procedures. Given the frequent use of percutaneous transluminal angioplasty (PTA) of the internal carotid artery (ICA) in acute settings, specialized simulation training is crucial. This study evaluates the feasibility of a custom-made ICA stenosis model for PTA simulation.

Methods: Internally developed 3D-printed circular clamps were attached to patient-based 3D printed ICA models and integrated into a previously described realistic whole-body neurovascular simulation model HANNES (Hamburg Anatomic Neurointerventional Endovascular Simulator) to simulate a proximal ICA stenosis. Participants (N = 5) of varying experience levels each performed three PTA procedures. Fluoroscopy time, radiation doses, and the extent of stenosis and balloon inflation pressure were assessed. After simulation, participants rated the model in terms of haptic, feasibility and applicability.

Results: For statistical analysis, the participants were divided into two groups according to their experience level. There was a statistically significant difference in the procedure duration between both groups, U = 10.500, Z = -1.968, p < 0.05. Significant test results could also be demonstrated for radiation doses (DAP) among groups, Kolmogorov-Smirnov p < 0.05, U = 7.000, Z = -2.357, p < 0.05. No difference was shown between the total contrast volume (ml) among groups that was used during procedures (m = 11.67, SD 2.09).

Conclusion: The authors propose a novel ICA stenosis simulation model for training of the cervical PTA. The model provides a realistic and replicable method for standardized procedural training.

Background and purpose: Molecular glioblastomas are challenging to distinguish from lower-grade diffuse astrocytomas (grades 2-3) without T2/T2 FLAIR mismatch, when assessed on T1-gadolinium and T2/T2 FLAIR MRI. This study aimed to evaluate the performance of the ADC from diffusion-weighted imaging and the relative CBV from DSC perfusion imaging in differentiating molecular glioblastomas from lower-grade diffuse astrocytomas.

Materials and methods: Fourteen patients with molecular glioblastomas (defined as isocitrate dehydrogenase wildtype (IDH-wt), exhibiting one or more of the following: telomerase reverse transcriptase (TERT) promoter mutation, epidermal growth factor receptor (EGFR) gene amplification, or +7/-10 chromosomal alterations, but without microvascular proliferation or necrosis) and thirteen patients with lower-grade diffuse astrocytomas (IDH-mutated or not elsewhere classified, grades 2-3) were included. ADC values and DSC-rCBV values were measured, and the two groups were compared using T‑test and Wilcoxon rank-sum test. Combinations of variables and tumor characteristics were analyzed using binary logistic regression, receiver operating curve (ROC) analysis, and Firth regression model.

Results: Molecular glioblastomas exhibited lower minimum ADC, mean ADC (p < 0.01), maximum ADC (p < 0.05) and higher standard deviation of ADC (p < 0.05), compared to lower-grade astrocytomas, measured in a 7 mm² ROI in the lowest ADC region. Molecular glioblastoma also had higher normalized median, average, and minimum rCBV ratios (p < 0.01) in a 10 mm² ROI in the highest perfused region. A combined receiver operating curve (ROC) model of ADC and rCBV achieved an area under the curve (AUC) of 0.93 (95% CI: 0.82-1.00).

Conclusions: This study demonstrates that ADC and rCBV measurements can help differentiate molecular glioblastomas from lower-grade diffuse astrocytomas lacking T2/T2 FLAIR mismatch. These findings may aid in preoperative tumor characterization, surgical planning, and prognosis.

Purpose: Direct oral anticoagulants (DOACs) have equivalent efficacy and fewer complications than vitamin K antagonists (VKAs) and are widely used for atrial fibrillation. However, data on how DOACs affect mechanical thrombectomy (MT) and influence the occlusion site are limited. This study aimed to investigate the efficacy and safety of MT before DOAC administration and how DOAC influences the occlusion site eligible for MT.

Methods: The NeuroEndovascular and Management from Multicenter Observation to Build a PHILosophical Approach (NEMMOPHILA) study analyzed 331 patients treated between January 2015 and March 2019 who underwent MT. The primary outcome was modified Rankin scale (mRS) of 0-3 at discharge, and the secondary outcomes included in-hospital mortality, and parenchymal hemorrhage (PH).

Result: Of the 331 patients, 39 had prior DOAC therapy, 25 had prior VKA therapy, and 267 had non- anticoagulant therapy (non-AC). The internal carotid artery (ICA) occlusion rate was significantly lower in the DOAC group (DOAC, 25.6%; VKA, 56.0%; non-AC, 45.3%; p = 0.030). No significant difference was found in the mRS at discharge (DOAC, 51.3%; VKA, 36.0%; non-AC, 50.9%; p = 0.354), mortality (DOAC, 7.5%; VKA, 7.9%; non-AC, 10.9%; p = 0.66), and PH (DOAC, 2.6%; VKA, 12.0%; non-AC, 9.0%; p = 0.362). Multiple regression analysis revealed that DOAC significantly reduced ICA occlusion (odds ratio, 0.429; 95% confidence interval, 0.195-0.943; p = 0.035).

Conclusion: Patients with prior DOAC had low ICA occlusion rates. DOAC administration history did not lead to mRS improvement at discharge and did not increase PH after MT.